Gayles was one of five students denied diplomas from the lone public high school in Galesburg after enthusiastic friends or family members cheered for them during commencement.

About a month before the May 27 ceremony, Galesburg High students and their parents had to sign a contract promising to act in dignified way. Violators were warned they could be denied their diplomas and barred from the after-graduation party.

Many schools across the country ask spectators to hold applause and cheers until the end of graduation. But few of them enforce the policy with what some in Galesburg say are strong-arm tactics.

"It was like one of the worst days of my life," said Gayles, who had a 3.4 grade-point average and officially graduated, but does not have the keepsake diploma to hang on her wall. "You walk across the stage and then you can't get your diploma because of other people cheering for you. It was devastating, actually."

School officials in Galesburg, a working-class town of 34,000 that is still reeling from the 2004 shutdown of a 1,600-employee refrigerator factory, said the get-tough policy followed a 2005 commencement where hoots, hollers and even air horns drowned out much of the ceremony and nearly touched off fights in the audience when the unruly were asked to quiet down.

"Lots of parents complained that they could not hear their own child's name called," said Joel Estes, Galesburg's assistant superintendent. "And I think that led us to saying we have to do something about this to restore some dignity and honor to the ceremony so that everyone can appreciate it and enjoy it."

In Indianapolis, public school officials this year started kicking out parents and relatives who cheer. At one school, the superintendent interrupted last month's graduation to order police to remove a woman from the gymnasium.

"It's an important, solemn occasion. There's plenty of time for celebration before and after," said Clarke Campbell, president of the Indianapolis school board.

In Galesburg, the issue has taken on added controversy with accusations that the students were targeted because of their race: four are black and one is Hispanic. Parents say cheers also erupted for white students, and none of them was denied a diploma.

Principal Tom Chiles said administrators who monitored the more than 2,000-seat auditorium reported only disruptions they considered "significant," and all turned in the same five names.

"Race had absolutely nothing to do with it whatsoever," Chiles said. "It is the amount of disruption at the time of the incident."

School officials said they will hear students and parents out if they appeal. Meanwhile, the school said the five students can still get their diplomas by completing eight hours of public service work, answering phones, sorting books or doing other chores for the district, situated about 150 miles southwest of Chicago.

Gayles' mother said she plans to fight the school board - in court in necessary - to get her daughter's diploma. The noise "was like three seconds. It was like, `Yay,' and that was it," Carolyn Gayles said.

American Civil Liberties Union spokesman Edward Yohnka said Galesburg's policy raises no red flags as long as it is enforced equitably. "It's probably well within the school's ability to control the decorum at an event like this," he said.

Another student who was denied her diploma, Nadia Trent, said she will probably let the school keep it if her appeals fail.

"It's not fair. Somebody could not like me and just decide to yell to get me in trouble. I can't control everyone, just the ones I gave tickets to," Trent said.